A while loop in Python is used to repeatedly execute code as long as the given condition is true.
To use a while loop we use the while condition:
syntax.
i = 1
while i <= 3:
print(i)
i += 1
1
2
3
Note: For simplicity we iterate over numbers with a number boundary condition (i <= 3
) in the example code. In practice however, a for loop usually is the better choice when we want to loop over numbers. A while loop can be used for more complex conditions.
The break statement
The break
statement can be used for an early stopping of the loop even if the loop condition is still True. Typically this is applied when another condition is met.
i = 1
while i <= 3:
print(i)
if i == 2:
break
1
2
A common use case of the break
statement is together with a while True
loop. This loop would run endlessly unless the break
statement is reached.
while True:
executed_code()
if something_special_happened:
break
The continue statement
The continue
statement is used to skip the current iteration.
i = 1
while i <= 3:
if i == 2:
break
print(i)
1
3
Note that here the print statement is applied at the end of each iteration, so after the possible continue
statement.